This vehicle has a driver door control module located inside the door that controls all of the functions of the switches in the driver door. It is not uncommon for these modules or the wiring to fail. You need to have someone that is familiar with these vehicles diagnose the problem using equipment that can communicate with this module and supporting wiring diagrams to pinpoint the problem. Generic OBD2 scan tools will be of no help. We use the factory MB Star Diagnostic System at our shop.
Good Luck,
James
EuroAsian Garage
Seatac, WA

Thank you for reply everyone, I try to drive to weekend and check it out again. I did search I found one the same my situations here is the link
http://repairpal.com/2000-mercedes-cl500-problems-832 I hope they can help me out on this